Change-gear mechanism.



H. HESS. CHANGE GEAR MECHANISM. APPLICATION FILED MAR.24, 1911.

Patented Mar. 12, 1912.

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COLUMBIA PLANOORAPH C0-.WAS!HNGTON, D. C.

H. HESS.

CHANGE GEAR MECHANISM.

APPLICATION FILED MAR 24, 1911.

Patented Mar. 12, 1912.

2 SHEETS-SHEET 2.

gnzanfoz atten w S W HENRY HESS, OF PHILADELPHIA, PENNSYLVANIA.

CHANGE-GEAR MECHANISM.

Specification of Letters Patent.

Application filed March 24, 1911.

Patented Mar. 12, 1912.

Serial No. 616,738.

To all whom it may concern:

Be it known that I, HENRY I-Inss, a citizen of the United States,residing at Philadelphia, in the county of Philadelphia and State ofPennsylvania, have invented certain new and useful Improvements inChange-Gear Mechanism, of which the following is a specification,reference being had therein to the accompanying drawing.

My invention relates to a change gear mechanism or what is sometimestermed variable speed gearing such as is used in various mechanicalsituations, sometimes, for example, upon machine tools or metal workingmachines of which the milling ma chine may be referred to as aninstance.

In mechanism of this class the problem is one of motion transmission,for example from a driving to a driven shaft with such control as topermit the relative speeds of the shafts to be changed; thus the drivingshaft may be steadily driven by power and the driven shaft may be causedto rotate at a greater or less speed according to the nature of theparticular work to be done on the milling or other machine. Togetherwith the driving and driven shafts in a change gear mechanism will beused a selective or shiftable keying or looking de vice for causing anyone of a number of gear-sets to be put into action intermediate of thetwo shafts so that the driven shaft speed will be in accordance with theproportions of the gear-set.

Change gears of the kind thus described are well known and an example isindicated as a part of the milling machine illustrated in U. S. LettersPatent No. 970,330, granted to me Sept. 13, 1910, in view of which thecooperative action of the gear-sets and the driving and driven shaftsand the selective locking device will be understood and will not requireto be described in any complete detail herein.

It is well known that there are many different specific uses made ofchange gear mechanisms requiring them to be of great diversity in size,operation, etc; for example the number of different ratios required in agiven change gear mechanism, the specific ratios to be comprisedtherein, the length or size of the mechanism and its mode of attachmentto the machine in connection with which it is to be used, will varyexceedingly between certain practical limits.

It is an object of the present invention to effect an important economyin the designing and constructing of change gear mechanisms bydispensing with the need of providing a special design and thereforespecial plans, patterns and castings for each mechanism, and this objectis accomplished by the present invention by enabling one to keep instock a comparatively small variety of parts capableof assemblage so asto make up the desired combination of parts and thus provide a changegear mechanism adapted for any given work to be performed. This isenabled because substantially all change gears, whatever the diversityof their work, have much in common. The expense of furnishing a changegear mechanism for any given service is thereby so far reduced as toconstitute a most important and desirable factor, due to the componentparts being manufactured in very much larger quantities.

To carry out the above referred to object, the present inventioncomprises an ex-. tensible case or casing in the nature of a housing,made up of a plurality of identical-meaning substantiallyinterchangeablecase units with and within which are associated thedriving and driven shafts, the different gear-sets intermediate theshafts and the selective means of putting the gearsets into action.

Further and more specifically stated objects, and the features of thisinvention for effecting them, will more fully appear and be set forth inthe following detail description.

I will first describe one form of change gear mechanism embodying thepresent improvements and will then point out the novel features in theclaims.

In the accompanying drawings forming a part hereof, Figure 1 is acentral vertical cross-section in which many of the interior partsappear in front elevation. Fig. 2 is a left end elevation, and Fig. 3 aright end elevation of the apparatus seen in Fig. 1. Fig. 4 is a frontelevation of the same with the parts, however, segregated or in theprocess of assemblage so as to more clearly disclose the manner in whichthe casing and the change gear mechanism as a whole are made up. Fig. 5is a perspective view of an intermediate half unit. Fig. 6 is a rightend view with an insertion enlarging the center distance between shafts.Fig. 7 is a view similar to that of Fig. 4 and combining with theelements of Fig. A the additional features shown in Figs. 5 and 6.

Similar letters of reference designate corresponding parts in theseveral figures of the drawings.

In the illustrated form of embodiment, the change gear mechanismincludes the following assembled elements, namely the housing or casewith the characteristics referred to, driving and driven shafts, anumber of selectable gear-sets, each one of which may differ from theothers not only as to ratios but as to its type, whether it be directlygeared, connected by chain, or merely an idler, a selective keying orlooking device, bolts binding the whole together, and means enabling thewhole to be secured in different ways to the machine toolsor the like.

I'have not shown the invention applied to y a machine tool, but wouldstate that it would preferably be introduced into that part of the trainof mechanism of the machine tool which would avoid an overstrain of thechange gear mechanism; thus where much 1 power has to be transmitted thechange gear mechanism would be introduced in the high speed end of thetrain where the tooth loads would be comparatively low.

In the drawings the driving shaft A may be said to extend longitudinallyand will preferably be paralleled by the driven shaft B. The former atits right-hand end will be connected in any desirable way to a source ofpower and the latter will become the source of movement for theoperative mechanism of the metal working or other machine. The drivenshaft B is shown as provided with a pulley Z) which may actuate a beltthat serves to connect it with some part of the mechanism of themachine.

Intermediate the driving and driven shafts are a number of gear-sets,and the number thereof may be varied in the use of my invention. Tengear-sets are shown, each of them operatively connected to both thedriving and driven shafts as by means of gear or sprocket wheels on saidshafts. The first or left-hand gear-set comprises a toothed sprocket orgear C on the driving shaft, and a corresponding one 0 on the drivenshaft, the two operatively connected at all times by a chain or sprocket0 this type of chain gear-set being well known and used in connectionwith a series of direct gear-sets for the purpose of permitting areversal of motion.

The second gear-set comprises a driving gear G and a driven gear a,mounted respectively on the driving and driven shafts, and the remaininggear-sets illustrated comprise driving gears C to C inclusive, anddriven gears c to c" inclusive respectively. The gears C to C aredirectly geared to the gears 0 to 0 the former being of graduateddiameters and the latter also graduated but in the inverse order asshown, thus preserving a uniform center distance between the gearscenters and affording various gear ratios as may be required by theworln It will be understood that the ratios of the several gear-setswill be calculated for whatever speed proportions are desired for thegiven metal working or other machine.

As is usual I prefer that the several driving gears C to C inclusiveshall be fast upon, so as to be compelled to drive with, the drivingshaft A, whereas the respective driven gears c to c are loose upon thedriven shafts but adapted to be selectively keyed or locked to thedriven shaft so that the latter shaft will be driven in accordance withthe ratio of the gear-set that includes the locked gear. A key a; isshown on the driving shaft serving to permanently look all of thedriving gears thereto. The different gear-sets may be renderedselectable by any desired selective devices, several forms of which arewell known, but I have shown a device in which the driven shaft has noendwise movement but is hollow so as to receive a sliding membercarrying a spline or key which may be pulled or pushed to any desiredposition so that-it may cause the driven shaft to be keyed or locked toany one of the gears thereon. This type of selective device isillustrated in Patent No. 970,380 before referred to, to which referenceis made for complete details.v In the drawings hereof the slide D iscapable of being pushed into or out of the hollow driven shaft, carryingwith it the pivoted spring pressed spline or key d shown in dotted linesin Fig. l as in a position to lock the driven gear 0 to the shaft. Theleftmost gear-set is shown in section, and this indicates the details ofthe selective mechanism. A slot in the driven shaft B permits the springpressed key (Z to pass through and project from the shaftinto'engagement with the free end of a coil spring d whose fixed end issecured in the hub of the gear or sprocket wheel 0. When the drivingshaft A is in rotation the driven gears including 0 will all beconstantly rotating, the effect of which is that the coil spring cl iscaused to contract and tighten itself upon the driven shaft B givingsuch engagement as to compel the latter to rotate with the gear 0. Ahand wheel 01 may be employed for adjusting the slide D by pushing orpulling it to the proper position, said slide having teeth along oneside engaging the teeth of the gear 03 mounted on a short shaft cl towhich the hand wheel d is also secured, so that rotation of the handwheel effects co-action between the gear and rack and causes the slidingof the slide D.

The case or housing of the present invention includes one or more, andin fact any desired number, of intermediate case units E, all of whichare mechanically speaking identical with each other or interchangeable,and also capable of being engaged or fitted one with the other so as topermit indefinite extension of the case or housing. These intermediatecase units are not shown as containing bearings for shafts or otherworking parts, and indeed the driving and driven shafts as indicatedhave their bearings at their respective ends, each of said shafts beingsufliciently long to accommodate all of the gear-sets so that the twoshafts are common toall of the gear-sets of my change gear mechanism.While the shafts might have their bearings directly in the frame of themetal working or other machine, which frame might also be recessed toaccommodate one or more of the gear-sets of the series, I prefer andhave indicated the employment of predesigned end units Fand G, the fourunits F, E, E and G of Fig. 1 with the mechanism contained with themconstituting a complete change gear mechanism. The left end section F isshown as having an extension f which affords an additional hearing forthe driven shaft, the pulley b being located between the extension f andthe end unit F. The right end unit G may have an extension 9 with anoffset 9 for properly supporting the hand wheel (Z and spline adjustinggear (Z As shown each of the end units F, G is constructed toaccommodate one or more gear-sets, and one of them F contains thegear-set C, 0 constituting the reverse gearset for the purpose ofreversing the direction of the driven shaft. Each of the intermediateunits E is shown as accommodating an integral plural number ofgear-sets, namely three. The different units are shown as joined to eachother at planes transverse to the driving and driven shafts.

It will be understood that the units E since they are shownnon-interchangeable with the end units F, G, may in all instances beproperly distinguished and designated by the term intermediate caseunits, that is to say, they are intermediate of whatever supporting orshaft bearing means or fittings may be employed at the two ends,examples of which are the illustrated end units. The term intermediatecase units therefore implies any sort of end supports or fittings.

Means for securing the whole together into an entirety is shown in theform of longitudinal bolts or rods I-I having heads h and nuts It, saidbolts adapted to be passed through from one end to the other and betightened upon the end units so as to compress all of the parts firmly,rigidly and permanently together; and each of the intermediate units maybe so designed that the bolts H will cooperate with them to pre venttheir lateral displacement, although in most cases they will besufficiently securely held merely by the great pressure of one againstthe other.

I will now describe the constructing or making up of a complete changegear mechanism from its component parts in accordance with my invention,so as to more clearly indicate the extensibility of the mechanism. Thedifferent component parts will be carried in stock, there beingcomparatively few kinds of parts. Thus the intermediate units E are allidentical and one stock design serves for them, so that a mechanism canbe built up with such stock parts, whether there be one, two, three ormore required to organize the desired combination. The end units F, Gare shown as identical, they having the extensions f and 9 attached tothem by bolts, screws or the like. Gear-sets will of course have to bekept in stock of all possible desired ratios, each gear-set or gear-pairhaving the requisite center distance to enable it to cooperate with thedriving and driven shafts A, B. The gears of the gear-sets preferablyhave hubs as shown, and the proportions of the different parts are suchthat each case unit or housing, whether an end unit or an intermediateunit, accommodates an integral number, namely two in the end units andthree in the intermediate units, of gearsets. Besides the end andintermediate units and the gear-sets, there will of course be kept instock shafting, binding bolts and the end fixtures f, g and theirconcomitants for example of the forms shown in the figures.

Suppose for a given metal working machine the call is made for a changegear mechanism to have a certain number of ratios, such as nine directratios and a reverse, or any other number, the change gear mechanismwill then be constructed or made up substantially as follows. Out ofstock will be selected the gear-sets according to the ratios called for,in this case nine direct gear-sets and one reserve. Remembering that theend case units accommodate one or more, in this case two, gear-sets,then suflicient intermediate units will be taken to accommodate theremainder, namely six gearing and binding bolts will be taken and cutoff if necessary so as to be of the proper length-for a combination oftwo end and two intermediate units. The driven shaft may then beconnected up to the left-hand end unit and secured in proper cooperationwith the pulley 5, extension f, etc. Then turning the parts aroundvertically if desired, the further assembling will be as clearlyindicated in Fig. 4. First three of the gear-sets will be strung uponthe respective shafts A, B. An intermediate housing or case unit E willthen be slipped over, it serving to inclose or accommodate the threegear-sets previously applied. Three further gear-sets will then beapplied, another intermediate case unit E, and thereafter any furthergear-sets and case units according to the demands. Finally the end caseunit G and the gear-sets it is to inclose will be fitted at the endleaving the driving shaft A sufiiciently projecting at the end. Theconnecting or binding bolts will then be passed longitudinally through,the end units having already been pre-arranged with holes to accommodatethem, and the binding nuts it will be securely tightened 1nto place. Thefitting of the selective device and hand Wheel will then be easilyaccomplished and the change gear mechanism is complete.

The present invention is shown as carried farther than above describedby the division of each of the end and intermediate units into two ormore identical fractional or half units, which in one sense may beconsidered as the ultimate units employed to build up the entiremechanism. Thus'the end unit F is divided into two half units F and Fthese being identical or interchangeable and being adapted to besecurely bolted together by bolts f and further bolts f if desired. Thesame is true of the end unit G, its halves G, G being connected by boltsg, 9 The intermediate sections E which are flanged at e to securegreater efiicacy in holding them in place, are indicated in Fig. 4 asdivided into half units E and E connected by bolts 6. The differentbolts f, g, e are externally disposed so as to keep the interior clearand afford greater facility in assemblage. The division of the differentunits into half units effects important economies in their manufactureand gives greater facility in the making up and assemblage. Theintermediate half units will all be identical and interchangeable andthe four end half units may also be identical and interchangeable, but Iprefer that the end half unit F be kept in stock of a slightly differentform affording a flat face f that may be easily machined off for thebetter reception of the base of the extension f.

In association with the main features of my invention above described,the following attaching means cooperates in an important manner.Attaching feet J are employed which are shiftable or securable at anyperipheral point on the change gear mechanism, preferably on theperiphery of the end units, and said feet have attaching flanges y"whereby they may be attached to the metal working or other machine atany convenient point thereof. This desirable result is shown as attainedby providing each of the end sections with a clrcular periphery, or oneconstituted of arcs of circles, and constructing also the feet J withcorrespondingly curved surfaces for contacting the circular peripheriesof the end sections. Thus at y" is indicated the circular periphery ofan end section, and at y' the curved surface of the foot J adapted tocontact therewith, and there being bolts, screws or the like j forsecuring the feet to the casing. By this arrangement the feet J may beattached at substantially any peripheral point in accordance with thesituation in which the change gear mechanism has to be employed, and inFig. 2 are indicated a number of possible positions for the attachingfeet, any one or two or more of which may be made use of at the sametime, the feet being identical or interchangeable.

The several half units contemplated in my invention, while shown ashaving circular peripheries, are not shown as constituting exactsemi-circles, but as seen in Figs. 2 and 8, each of them is considerablymore than a semi-circle, this alfording a superior shape for theaccommodation of the shafts and the gears, and also increasing thestrength of the mechanism by affording a greater resistance to collapse.

An insertion L is shown in Fig. 6 for enlarging the center distancebetween shafts A and B to accommodate larger sets of gears. In the mainfigures of the drawings pins 70 are shown for determining andmaintaining the adjustment of one half unit to another, and wheninsertion L is used it may be recessed on opposite sides at Z as shown,so as to accommodate two sets of pins is instead of the single set asshown in the main figures.

Fig. 7 is a view similar to Fig. 4, it showing substantially all of thecomponent parts in a position preparatory to their assemblage, and inthis figure will be seen designated by letter the several insertions Lbe tween the several pairs of half units which are for the purpose ofenlarging the center distance between the shafts A and B, as explainedin the previous paragraph above. Fig. 7 also shows in dotted lines theinternal flanges 6 formed on each half unit and similar flanges Z formedon each insertion L.

It will be seen that by reason of the construction including the designsand arrangements above shown and described, a change gear mechanism 'isprovided which answers the objects and affords the advantages of theinvention as hereinbefore set forth, and other advantages will beapparent to those skilled in the art.

It is to be understood that the invention in its broader aspects is notlimited to the precise construction shown nor to any particularconstruction by which the invention has been or may be carried intoeffect, since many changes may be made in the details of the partswithout departing from the main principles of the invention and with outsacrificing its chief advantages; and no limitations are intended exceptsuch as are set forth in the respective claims.

hat I claim and desire to secure by Let ters Patent is:

1. A change gear mechanism comprising an extensible case made up ofcomponents including a plurality of identical intermediate case units,in combination with driving and driven shafts, a number of gear-setsintermediate said shafts and a selective means of putting said gear-setsinto locked relation to the shafts.

2. A change gear mechanism comprising a longitudinally extensible casemade up of components including a plurality of identical intermediatecase units joined to each other at planes transverse to the driving ordriven shafts, in combination with driving and driven shafts, a numberof gear-sets intermediate said shafts and a selective means of puttingsaid gear-sets into locked relation to the shafts.

3. A change gear mechanism comprising a longitudinally extensible casemade up of components including a plurality of identical intermediatecase units joined to each other at planes transverse to the driving ordriven shafts, in combination with driving and driven shafts, a numberof gear-sets intermediate said shafts a selective means of putting saidgear-sets into locked relation to the shafts; and longitudinal bindingmembers securing the several ease units together.

4. A change gear mechanism comprising in combination the driving anddriven shafts, a number of gear-sets intermediate said shafts, aselective device, and an extensible case made up of components includingidentical intermediate case units surrounding said shafts and gear-sets,with means for securing the whole together.

5. A change gear mechanism comprising in combination the driving anddriven shafts, a number of gear-sets intermediate said shafts, aselective device, and an extensible case made up of end case unitshaving shaft bearings and identical intermediate case units surroundingsaid shafts and gearsets, with means for securing the whole together. v

6. A change gear mechanism comprising in combination driving and drivenshafts,

selectable gear-sets, and an extensible case made up of componentsincluding a plurality of identical intermediate case units.

7 A change gear mechanism comprising in combination driving and drivenshafts, selectable gear-sets, and an extensible case made up ofcomponents including a plurality of identical intermediate case units,each unit corresponding in longitudinal dimension with a given number ofthe gear-sets.

8. A change gear mechanism comprising in combination driving and drivenshafts, selectable gear-sets, and an extensible case made up ofcomponents including a plurality of identical intermediate case units,each unit being formed in two identical half units on a plane parallelto said shafts.

9. A change gear mechanism comprising in combination driving and drivenshafts, selectable gear-sets, and an extensible case made up ofcomponents including a plurality of identical intermediate case units,each unit being formed in two identical half units on a plane parallelto said shafts, and enlargeable by insertion of a piece between saidhalf units.

10. A change gear mechanism comprising in combination driving and drivenshafts, selectable gear-sets, and an extensible case made up of aplurality of case units, each unit being formed in two identical halfunits on a plane parallel to said shafts.

11. A change gear mechanism comprising in combination driving and drivenshafts, selectable gear-sets, and an extensible case made up of aplurality of case units, each unit being formed in two identical halfunits on a plane parallel to said shafts, and enlargeable by insertionof a piece between said half units.

12. A change gear mechanism comprising in combination driving and drivenshafts, selectable gear-sets, and an extensible case made up of aplurality of case units, at least one of said units having a circularperiphery, and curved attaching feet securable at any peripheral pointfor mounting the mechanism on a machine.

13. A change gear casing made up of components including a plurality ofidentical casing units, each unit consisting of a shell having provisionfor adjustment to the adjacent unit, and means for rigidly securing thewhole together.

14. A change gear mechanism made up of components including a pluralityof identical casing units, each unit consisting of a shell having aninward flange at each end, and bolts for securing the whole together.

15. A change gear mechanism made up of sisting of a shell forming aportion of a circomponents including a plurality of identical casingunits, each unit consisting of two or more identical fractional units,means for securing such fractional units together to cle greater than asemi-circle, and means for securing all said half units and unitstogether.

In testimony whereof I affix my signature form a unit, and other meansfor securing in presence of tWo Witnesses.

the units together.

16. A change gear mechanism made up of components including a pluralityof identical casing units, each unit consisting of two identical halfunits and each half unit concopies of this patent may be obtained forfive cents each, by addressing the Commissioner of Patents.

HENRY HESS.

Witnesses:

THEO. H. MCALLA, NETTIE L. HAHN.

Washington, D. G. 1

